Rodriguez, Daniel

This work uses computational fluid dynamics to study the flowfield around a
hypersonic missile with two lateral jets to provide control in place of control surfaces.
The jets exhaust an H2-O2 mixture at Mach number of 2.9 with a jet pressure ratio of
roughly 10,500. The jets are staggered axially and circumferentially in such a way to
produce pitch and yaw. The flowfield of such a jet configuration is characterized at
several angles of attack and the corresponding force coefficients and amplification factors
are provided. The freestream air and H2-O2 plume is treated as inert for the majority of
the calculations. Special cases are treated with finite rate chemical kinetics and compared
to the inert flowfield to ascertain the effects that chemical reactions have on the force
coefficients. It was found that the flowfield was only slightly altered from the familiar
one jet flowfield when the second jet is active. The flow topology and vortex structures
tend to shift towards the second jet but the overall structure remains the same. The
normal force amplification factors are close to unity over the range of angle of attack due to the thrust being so high with the two jet configuration having a lower amplification
factor compared to firing a single jet. Treating the flowfield as chemically reacting did
not affect the force values much: the difference being 0.3% for an angle of attack of 0°.

A sudden expansion combustor (SUE) is analyzed using computation fluid dynamics (CFD). CO emissions and NOx emissions are computed for various operating conditions of the SUE combustor using a can type and an annular type geometrical configurations. The goal of this thesis is to see if the SUE combustor is a viable alternative to conventional combustors which utilize swirlers. It is found that for the can type combustor the NOx emissions were quite low compared to other combustor types but the CO emissions were fairly high. The annular combustor shows better CO emissions compared to the can type, but the CO emissions are still high compared to other combustors. Emissions can be improved by providing better mixing in the primary combustion zone. The SUE combustor design needs to be further refined in order for it to be a viable alternative to conventional combustors with swirlers.